Apr 19, 2024 - News

Rare cicada co-emergence won't hit Philadelphia

Illustration of cut-paper cicadas swarming.

Illustration: Maura Losch, Shoshana Gordon/Axios

Several states are bracing for a potential cicada invasion in the coming months.

Why it matters: Two specific broods of droning cicadas are expected to emerge from the ground simultaneously this spring, which hasn't happened in more than 200 years or when Thomas Jefferson was president.

Yes but: Philadelphia doesn't have to bug out: The next specific periodical cicadas won't emerge here for several years.

Driving the news: The cicada spectacle of Broods XIII and XIX emerging will affect several Midwestern and Southern states, including Iowa, Texas and Georgia.

  • Southern Maryland is the closest place to Philly expected to be affected, which is about 180 miles away

Between the lines: The 15 surviving periodical cicada broods emerge from their 13- or 17-year life cycles in general geographic areas and don't migrate, Sean O'Donnell, a biologist at Drexel University, tells Axios.

Check out the full project from Axios Visuals

Be smart: While the insects can come in great numbers and bring deafening sounds, they're more of a nuisance and don't bite or cause harm to agriculture.

State of play: The Philly region's annual cicadas will emerge in their largest numbers around August, O'Donnell says.

Threat level: Brood XIX will emerge next year in most parts of Pennsylvania, but not in Philly or the north and northwest parts of the state.

  • In 2030, Brood II will emerge in Philly proper and other parts of the Northeast.
Data: USDA and University of Connecticut; Graphic: Jared Whalen, Will Chase and Kavya Beheraj/Axios

The intrigue: The largest number of cicadas are estimated to come in 2089 during another double brood co-emergence.

  • More than 15 trillion bugs could appear over several states, including Philly and other parts of Pennsylvania.
  • The fine print: The numbers used in these estimates are extremely rough approximations.

What they're saying: Cicadas have one of the longest insect life cycles, which helps them avoid predators, O'Donnell says.

  • "This is an amazing example of animals adapting their lifecycle to their environment and to the challenges they face," he said.

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